LG Error Code & PCB Burnout

[Rtic]

Hi Guys

I've just been to an LG LIBRO which is not operating on cooling or heating. The indoor unit lights are flashing a sequence, which I assume is indicating an error code, but I can't find error codes for this model anywhere; could someone enlighten me please

COOLING LIGHT BLINKS 7 Times
Then
HEATING LIGHT BLINKS 6 Times

Anyhow, I isolated the power and switched the A/C back on, which wipes out the error messgae. The compressor strikes up for about 30 seconds then cuts out; the condensor fan motor does not strike up. Gas pressures are correct.

I had a look at the PCB and found that a ladybird has sat on one of the PCB solder points and blown up! I suspect this the problem, and will get the PCB sent off to be repaired & tested. I've attached the pictures; anyone who knows these PCBs confirm that this point being burnt out would cause the symptoms shown above?

Many Thanks

JV

13948

[Brian_UK]

Only a new pcb will answer your question I suspect.

Without it running you cannot say that the gas pressure is okay.

[Tayters]

Not got a manual for that but from what I've seen LG codes are standard across the range (almost!).

If that code is 67 then: 67
Outdoor Fan Motor siezed, or rotation sensing circuit failure. Check motor for mechanical and/or electrical failure, if okay replace pcb.

Best confirm the code with LG. To test the motor, red wire on it's own is 300 ish VDC, next is the neutral then 15V DC to power internal PCB of fan motor, other two are speed command and speed output.
You can check the power supplies and do a diode test of the motor. http://www.refrigeration-engineer.com/forums/showthread.php?39948-fujitsu-AOH45LJBYL&p=283691&highlight=#post283691 post 12 and homage due to Mr Ozairman.

Power down for a couple of mins before unplugging fan motor as high voltage can spark across knackering PCB and motor!
Looks like the ladybird sat on a pin connected to the neutral so might have caused this issue.

Just to reiterate that this is assuming error code is 67 and this means the above code and we all know what assuming is the mother of!

Cheers,
Andy.

[Rtic]

Only a new pcb will answer your question I suspect.

Without it running you cannot say that the gas pressure is okay.

Hi Brian – Hope retirement is treating you well you lucky sod!

OK, maybe getting ahead of myself with guessing the charge is right. However for the 30 seconds that it runs (on cooling from memory) I get up to 20bar on the high side & down to 8 Bar on low side before it cuts out, so on r410, charge looks ok for the minimal time that I have to look at it. However, at the point when the high side reaches 20bar, I would expect the condenser fan to engage so I would guess that burned out point relates somehow to the condenser fan.

No need to replace the PCB I hope, only needs a small solder! I would do it myself, but I like to send it off, because they can test the components to make sure the burnout hasn’t effected anything else on the PCB

Anyone shed any light on the above error code please?

[Rtic]

Not got a manual for that but from what I've seen LG codes are standard across the range (almost!).

If that code is 67 then: 67
Outdoor Fan Motor siezed, or rotation sensing circuit failure. Check motor for mechanical and/or electrical failure, if okay replace pcb.

Best confirm the code with LG. To test the motor, red wire on it's own is 300 ish VDC, next is the neutral then 15V DC to power internal PCB of fan motor, other two are speed command and speed output.
You can check the power supplies and do a diode test of the motor. http://www.refrigeration-engineer.com/forums/showthread.php?39948-fujitsu-AOH45LJBYL&p=283691&highlight=#post283691 post 12 and homage due to Mr Ozairman.

Power down for a couple of mins before unplugging fan motor as high voltage can spark across knackering PCB and motor!
Looks like the ladybird sat on a pin connected to the neutral so might have caused this issue.

Just to reiterate that this is assuming error code is 67 and this means the above code and we all know what assuming is the mother of!

Cheers,
Andy.



Thanks Andy

That’s great info. I will confirm the error code with LG tomorrow, but would guess this is spot on, as the high side reaches 20bar before in cuts out. So I would guess that the PCB is calling for the condenser fan motor with no results; highly likely due to this burned out point.

Thanks again, and will let you know the result after the repair

[Brian_UK]

You could find that the fan motor is faulty because they can backfeed the pcb thereby blowing them up.